Thread gauge



E. BUCKI NG HAM THREAD GAUGE Filed April 23, 1923 INVENTGR BYE;

ATTQRNEY Patented Apr. 2%, 1925.

I EARLE BUGKING-HAM, OF HARTFQRD, CONNECTICUT, ASSIQNOE 'ro PRATT &W'ENM consensus, on NEW roux,

N. If, A CQEEUMTIQN QF NEW JEMEY.

runner sauce.

Application filed April 1923. erial lilo. elitist.

provide a combmation thread gauge particularly adapted to determine thecorrectness of the taper of threaded conical surfaces and the accuracyof the lead of the thread therein. More particularly, the inventionrelates to a thread gauge for measuring the accuracy of Briggs standardpipe threads commonly used for .pipes and pipe fittin s.

It IS an object of the invention to provide an improved thread gaugeparticularly ada ted to determine the accuracy of the lea of screwthreads.

Another object of the invention is to provide gauges of the above typesadapted to perform the measuring functions stated either on external orinternal threaded surfaces.

With the above and other objects in view, my invention consists in thefeatures of construction and operation set forth in. the followingspecification and illustrated in the accompanying drawing. In suchdrawing annexed hereto and forming a part of this specification, l haveshown my invention embodied respectively in taper thread gauges forinternal and external threaded surfaces but it will be understood thatthe inventiont0 can be otherwise embodied and that the drawing is not tobe construed as defining or limiting the scope-of the invention, theclaims appended to this specification being relied upon for'thatpurpose.

Referring to the figures of thedraw'ing:

Figure 1 is a side elevation partially in section of one form of myimproved thread gauge illustrated as being in gaging contact with theconical threaded bore of a the gauge.

- line 33 of Fig. 1.

.While in the drawing master ring gauge, the said ring gauge being Fig.3 is a cross section thereof talren on till Fig. l is a longitudinalsectional view of a modified form of my invention adapted to measureinternal threaded surfaces, such gauge being illustrated as mounted on amaster plug gauge.

Fig. 5 is a side elevation thereof. As illustrated in the drawing, myinvention comprises two relatively spaced and relatively movable gagingmembers each provided with means, as the screw threads illustrated, forengaging the threads of the surface to be measured or gauged. Asillustrated in the drawing, these gaging members are coaxial and each isadapted to engage a portion of the screw threaded sur face being gaged.Means including duations are provided on the members for indicating theconical or taper accurac of the surface and the accuracy of the lea ofthe thread therein, such means functioning by E the axial relativespacing of and the relative angular position ofthe said two' members; lhave illustrated my invention in connection with a combination taper andlead measuring thread gauge, it should be understood that the inventionis capable of various other embodiments not limited to the detailsillustrated. lhe in vention illustrated will now be specificallydescribed.

The gauge shown in Figs. 1, 2 and 3 for testing internal threadedsurfaces or bores will first he described. This gauge comprises a pairof gaging members i and 2 each .havm two or three convolutions bf 90accurately termed standard screw threads of 1 the size and type of thosein the threaded till bore to hegaged. Integral with the gaging member 1is an axial y extending sleeve 3 knurled on its exterior surface toprovide a hand grip. The memher 2 is of dish-like formv and has integraltherewitha shank-d adapted to extend axially through the sleeve 3. Thenon-gaging end of the shank is reduced at 5 in a manner to provide ashoulder 6. f

Screw threaded to the end 7 of the sleeve is a. cap 8 fitting over thereduced shank end 5 and engaging the shoulder d. The threads 7 are ofexactly the same itch as 1% the threads 1. The cap 8 is provi ed withice I graduations 9 thereon adapted to cooperate corresponding to theparticular bore to be gaged but also must correspond to the particularform and leadof the screw threads.

This may conveniently be done by securing the two gauge members 1 and 2together in the pro er relative position and finishing the screw t readsthereon to a master gauge as exactly 'threaded into the conical bore tobe gaged The member 1 is thereafter threade intothe bore as far as itwill readily go. If the if the gagin members 1 and 2 were, one solidmember. ith the aging members in the position just define the cap 8 isscrew threaded onto the sleeve until the same'rests firmly on theshoulder 6 of the shank 4.

With the several parts of the gauge in this correct relationship, thegraduations 9 and '11 andthe cooperating indicia marks 10 and 12' areformed, the mark 10 being made to exactly register with the zero on thegraduajtions 9 and the mark .12 bein made to register with the zero on te graduations 11. I J Y 1 In operation, the member- 2 is first taper ofthe bore is correct, the members 1 and 2 should be relatively spaced thesame distance a art aswhen originally formed and threadied to the mastergauge as above defined. The accuracy of the taper may be observed by the'graduations 9 and 10. If the taper is correct the indicia line 10 willregister exactly with the zero on the graduations 9. If, however, the tar is not corroot the gaging member 1 wi be in contact with. the boreslightly closer to or further from the other agin member 2. This willnecessitate a t rea mg of the sleeve" 3 further into or out of the cap 8to contact the cap with the shoulder (yand the line 10 will notthereafter register with the said zero. In Figs. 1 and 2, the gauge isshown in gaging contact with the threaded bore of a master ring gauge13. The threaded bore of this ring gauge is of correct taper andtherefore the line 10registers exactly with the zero on graduations 9.

In the lead of the thread is correct, the

- zero on the graduations 11 will register with the indicia line 12 inthe same manner as when the gauge was formed and threaded to the mastergauge as above defined.

Should the lead of the thread be greater or' less than the standard,however, the memhers I and 2 will be in a different relative angularposition from-that shown in Fig.

' readily .the face 14 of the ga rect. In 1 and 2, the lead of the '70threads in the ring gauge 13 iscorrect and the zero of graduations 11 istherefore in exact registry with the indicia line 12.

It should be understood that the taper and lead measurements are quiteindependent of 18 each other. Any inaccuracy of taper causes the members1 and 2 to be s aced axially nearer to or further from eac h other thanthe standard or accurate position shown in Fig. 1. Such a change causesthe shoulder 6 to be spaced a dillerent distance away from the end ofthesleeve 3. This change of course, requires a rotary adjustment of the cap8 in one direction or the other on the sleeve which adjustment indicatesby the graduations 9 the amount of plus or minus taper inaccuracy. Itwill be noted, however, that such inaccuracy in no way disturbs thethread lead reading at 11 and 12, as the member Swill, in its gaginposition, be moved to but against the en 6 of member 4. Since thethreads 7 and 1 are of the same ,pitch, the screwing of the cap 8further or less onto the threads 7 causes the same rotation of the capon the shank 4 as though the member 1 were being screwed within the workpiece. It should be understood that in the gauge reading position, thecap 8 is always in contact with the shoulder 6.

Likewise any inaccuracy of the lead, the taper bein correct, causes agreater or less rotation o the member 1 to place the same in therelative axial position illustrated in Fig. 1. The cap 8 must berotatably adjusted on the sleeve and shank 4, in engaging,

the same with the shoulder 6, to allow for this difference. Suchadjustment of the. ca leaves'the zero of graduations 11 to one si e orthe other of the graduation mark 12 whereby to indicate the inaccuracyof lead.

It will therefore be understood that any inaccuracy of taper or threadlead or both is indicated by the gauge independof each other.

entl The gaging member 1 is also referably cutaway at 14 to provide ashoul er for indicating the diameter accurac of the opening being gaged.It will understood that if in the measuring operation the member 1enters the opening 'suflicientl to bring uge flush wit the face of themember bemg gaged, the diameter of the opening is correct andaccurate.

In Figs; 4 and 5, I have shown a modified form of the invention ada tedto be applied to the gaging of externa tapered; threads such as arecommon y used on the ends of pipes or other bodies. This modificationcomprises gaging members or rings 15 ml 16 internally threaded at 17 and18 respoc tively. Intermediate the rings is a member 19 threaded to thering 16 at 20, the threads 20 being of the same pitch as the threads 18.The periphery of the member 19 is graduated at 21 to cooperate with agraduation 15 and is graduated at mark 22 on the rin a graduation mark24 23 to cooperate wit on the-ring 16.

The rings 16 and 19 are threaded at 20 and the ring 19 is threadedlyengaged with the rin 16 as illustrated. The internal surfaces tion, thering 19 is rotated on the member 16 until the forward face thereofcontacts firmly with the member 15. With the several parts'of the gaugein this-correct relationship, the graduatlons 21 and 23 and thecooperating indicia marks 22 and 24 are formed, the mark 22 being madeto exactly register with the zero on the graduations 21 and the mark 24being made to exactly register with the zero on the graduations 23.'

The indicia 21, 22 are adapted to indicate the lead accuracy of thescrew threads and the indicia 23, 24 are adapted to indicatethe $5 taperaccuracy.

scribed and as'shown in tld The operation of the gauge shown in Figs. 4and 5 is substantially the same as that of the gauge shown in Figs. 1, 2and 3 heretofore described. A full repetition of such operation istherefore believed unnecessary.

,The external threaded surface to be tested is first threaded to thegauge as heretofore deig. 4. The ring 19 is rotated to seat the samefirmly against the member 15. If the lead is correct, the mark 22 willbe in exact re ister with the zero of the graduations 21. fiikewise ifthe taper is correct the mark 24 will be in exact register with the zeroof the graduations 23. In Figs. 4 and 5. the, gauge is shown in contactwith a master nluggauge 25. The taper and lead of the thread gagingportion of this master (gauge is correct and therefore the said in iciaregister exactly with the said zeros, as illustrated.

What I claim is: 1. A gau e for testing the taper and lead of threadeconical surfaces comprising in combination, a threaded gaging memberadapted to contact with a portion of the threaded conical-surface to begaged, a sec ond threaded gaging member adapted to contact with anotherportion of said threaded surface, means co-operating with the saidmembers to indicate the conical or taper accuracy of the surface, andmeans movably mounted on one of the members and cooperatlng with theother member for indicating &

the accuracy of the lead of the thread being gaged.

2. A gauge for testing the taper and lead of threaded conical surfacescomprising in combination, a threaded gaging member adapted tocontactwith a portion of the threaded conical surface to be gaged, asecond threaded aging member adapted to contact with anot er portion ofsaid threadmembers to indicate the conical or taper accuracy of thesurface, and means threaded to one of the members and contacting withthe other member for indicating the accuracy of the lead ofthe threadbeing gaged.

ed surface, means cooperating with the said 3. A gauge for testing thetaper and lead 2 of threaded conical surfaces comprising 1n combination,a threaded gaging member adapted to contact with a portion of thethreaded-conical surface to begaged., a second threaded gaging memberadapted to contact with another portion of the said threaded surface,means functioning by the axial relative spacing of the said two membersfor indicating the conical or taper accuracy of'the surface, and meansthreaded to one of the members and cooperating with the other, memberfor indicating the accuracy of the lead of the thread being gaged.,

the said lead being measured by the rotary position of the last namedmeans.

4. A gauge for testingthe taper and lead of threaded conical surfacescomprising in combination, a threaded gaging member.

adapted to contact with a portion of the threaded conical surface to begaged., a second threaded gaging member adapted to contact with anotherportion: ofthe said threaded surface, means functioning by the axialrelative spacin of the saidtwo membars for indicatin t e conical ortaper accuracy of the sur ace, one ofthe members being provided withother screw threads thereon. of a itch corresponding exactly to thepitch of t e threads on the gaging portion thereof, and means threadedto the said other screw threads and cooperating with the other memberfor indicating the accuracy of the lead of the thread being gaged, thesaid lead being measured by, the rotary position of the last namedmeans.

5; A gauge for testing the taper and lead of threaded conical surfacescomprising in combination, a gaging member having a threadedportionadapted to contact with a res means on the said shank and sleeve toindicate the conical or taper accuracy of the surface and the accuracyof the lead of the thread therein.

6. A gauge for testing the lead of screw threads comprising incombination, a threaded gaglng member adapted to contact with a portionof the threaded surface to adapted to contact with another portion ofthe said threaded surface spaced axially from the first portion, meansto determine the distance apart of said threaded portions,

and means cooperating with the said mem bers for indicating theirrelative angular positions to determine the accuracy of lead of thethreads being gaged.

7. A gauge for testing the lead of screw ;hreads comprising incombination, a threaded gaging member adapted to contact with a portionof the threaded surface to be gaged, a second threaded gaging memberadapted to contact with another portion of the said threaded surfacespaced axially from the first portion, means to determine the distanceapart of said threaded portion, the ,said'members being coaxial, andmeans cooperating with the said members for indicating their relativeangular osition's to determine the accuracy of lead '0 the threads beinggaged.

i 8. A gauge for testing the lead of screw threadscomprising incombination, a threaded gaging member adapted to con- I tact with a(portion of the threaded surface to be gage a second threaded gagingmember adapted to contact with another portion of the said threadedsurface,' one of I the members being provided with other screw 40threads thereon of a pitch corresponding be gaged, a second gagingmemben exactly to the pitch of the threads on the gaging portionthereof, and means threaded to the said other screw threads andcooperating with the other member for indicating the accuracy of lead ofthe threads being gaged, the'said lead being measured by the rotaryposition of the last named means.

9. A gauge for testing the lead of screw threads comprising incombination, a 'threaded gaging member adapted to contact with a portionof the threaded surface to be gaged and having a sleeve extendingaxially therefrom, a second threaded gaging member adapted to contactwith another portion of the said threaded surface and having a shankextending axially therefrom within the sleeve, and means cooperatingwith the said shank and sleeve for indicating the accuracy of lead ofthe threads bea 10.. A gauge for testing the lead of screw .threadscomprising in combination, a threaded gaging member adapted to contactwith a portion of the threaded surface to be gaged and having a sleeveextending axially therefrom, a second threaded gaging memher adapted tocontact with another portion of the said threaded surface and havin ashank extending axially therefrom wit in the sleeve, and means threadedto the sleeve and co-operating with the shank for indicating theaccuracy of the lead of the thread being gaged, the said lead beingmeasured by the rotary position of the last named means relative to thesleeve.

In testimony whereof, I hereto afiix my signature.

EARLE BUCKINGHAM.

